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Date: Wed, 25 Apr 2012 19:51:44 +0800
From: Cong Wang <xiyou.wangcong@gmail.com>
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To: Konstantin Khlebnikov <khlebnikov@openvz.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/4] compiler.h: introduce unused_expression() macro
References: <20120425112623.26927.43229.stgit@zurg>
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On 04/25/2012 07:26 PM, Konstantin Khlebnikov wrote:
> Sometimes we want to check some expressions correctness in compile-time without
> generating extra code. "(void)(e)" does not work if expression has side-effects.
> This patch introduces macro unused_expression() which helps in this situation.
>

Interesting, I am wondering why gcc doesn't eliminate the code as we 
pass either -O2 or -Os to it.